lib/libutil/login_ok.c

/*-
 * Copyright (c) 1996 by
 * David Nugent <davidn@blaze.net.au>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice immediately at the beginning of the file, without modification,
 *    this list of conditions, and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. This work was done expressly for inclusion into FreeBSD.  Other use
 *    is permitted provided this notation is included.
 * 4. Absolutely no warranty of function or purpose is made by the authors.
 * 5. Modifications may be freely made to this file providing the above
 *    conditions are met.
 *
 * Support allow/deny lists in login class capabilities
 *
 *	$Id$
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <ttyent.h>
#include <fnmatch.h>

#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/param.h>
#include <login_cap.h>


/* -- support functions -- */

/* login_strinlist()
 * This function is intentionally public - reused by TAS.
 * Returns TRUE (non-zero) if a string matches a pattern
 * in a given array of patterns. 'flags' is passed directly
 * to fnmatch(3).
 */

int
login_strinlist(char **list, char const *str, int flags)
{
  int rc = 0;

  if (str != NULL && *str != '\0')
  {
    int i = 0;
    while (rc == 0 && list[i] != NULL)
      rc = fnmatch(list[i], str, flags) == 0;
  }
  return rc;
}


/* login_str2inlist()
 * Locate either or two strings in a given list
 */

int
login_str2inlist(char **ttlst, const char *str1, const char *str2, int flags)
{
  int rc = 0;

  if (login_strinlist(ttlst, str1, flags))
    rc = 1;
  else if (login_strinlist(ttlst, str2, flags))
    rc = 1;
  return rc;
}


/* login_timelist()
 * This function is intentinoally public - reused by TAS.
 * Returns an allocated list of time periods given an array
 * of time periods in ascii form.
 */

login_time_t *
login_timelist(login_cap_t *lc, char const *cap, int *ltno, login_time_t **ltptr)
{
  int j = 0;
  struct login_time * lt = NULL;
  char **tl = login_getcaplist(lc, cap, NULL);

  if (tl)
  {
    while (tl[j++] != NULL)
      ;
    if (*ltno >= j)
      lt = *ltptr;
    else if ((lt = realloc(*ltptr, j)) != NULL)
    {
      *ltno = j;
      *ltptr = lt;
    }
    if (lt != NULL)
    {
      int i = 0;
      --j;
      while (i < j)
      {
	lt[i] = parse_lt(tl[i]);
	++i;
      }
      lt[i].lt_dow = LTM_NONE;
    }
  }
  return lt;
}


/* login_ttyok()
 * This function is a variation of auth_ttyok(), but it checks two
 * arbitrary capability lists not necessarily related to access.
 * This hook is provided for the accounted/exclude accounting lists.
 */

int
login_ttyok(login_cap_t *lc, const char *tty, const char *allowcap, const char *denycap)
{
  int rc = 1;

  if (lc != NULL && tty != NULL && *tty != '\0')
  {
    struct ttyent * te = getttynam(tty);  /* Need group name */
    char * grp = te ? te->ty_group : NULL;
    char **ttl = login_getcaplist(lc, allowcap, NULL);

    if (ttl != NULL && !login_str2inlist(ttl, tty, grp, 0))
      rc = 0;	/* tty or ttygroup not in allow list */
    else
    {
      ttl = login_getcaplist(lc, denycap, NULL);
      if (ttl != NULL && login_str2inlist(ttl, tty, grp, 0))
	rc = 0; /* tty or ttygroup in deny list */
    }
  }
  return rc;
}


/* auth_ttyok()
 * Determine whether or not login on a tty is accessible for
 * a login class
 */

int
auth_ttyok(login_cap_t *lc, const char * tty)
{
  return login_ttyok(lc, tty, "ttys.allow", "ttys.deny");
}


/* login_hostok()
 * This function is a variation of auth_hostok(), but it checks two
 * arbitrary capability lists not necessarily related to access.
 * This hook is provided for the accounted/exclude accounting lists.
 */

int
login_hostok(login_cap_t *lc, const char *host, const char *ip, const char *allowcap, const char *denycap)
{
  int rc = 1; /* Default is ok */

  if (lc != NULL && ((host != NULL && *host != '\0') || (ip != NULL && *ip != '\0')))
  {
    char **hl = login_getcaplist(lc, allowcap, NULL);

    if (hl != NULL && !login_str2inlist(hl, host, ip, FNM_CASEFOLD))
      rc = 0;	/* host or IP not in allow list */
    else
    {
      hl = login_getcaplist(lc, "host.deny", NULL);
      if (hl != NULL && login_str2inlist(hl, host, ip, FNM_CASEFOLD))
	rc = 0; /* host or IP in deny list */
    }
  }
  return rc;
}


/* auth_hostok()
 * Determine whether or not login from a host is ok
 */

int
auth_hostok(login_cap_t *lc, const char *host, const char *ip)
{
  return login_hostok(lc, host, ip, "host.allow", "host.deny");
}


/* auth_timeok()
 * Determine whether or not login is ok at a given time
 */

int
auth_timeok(login_cap_t *lc, time_t t)
{
  int rc = 1; /* Default is ok */

  if (lc != NULL && t != (time_t)0 && t != (time_t)-1)
  {
    struct tm * tptr = localtime(&t);

    static int ltimesno = 0;
    static struct login_time * ltimes = NULL;

    if (tptr != NULL)
    {
      struct login_time *lt = login_timelist(lc, "times.allow", &ltimesno, &ltimes);

      if (lt != NULL && in_ltms(lt, tptr, NULL) == -1)
	rc = 0;	  /* not in allowed times list */
      else
      {
	lt = login_timelist(lc, "times.deny", &ltimesno, &ltimes);

	if (lt != NULL && in_ltms(lt, tptr, NULL) != -1)
	  rc = 0; /* in deny times list */
      }
      if (ltimes)
      {
	free(ltimes);
	ltimes = NULL;
	ltimesno = 0;
      }
    }
  }
  return rc;
}